Preparation and characterization of low density polyethylene‐agar biocomposites: Torque‐rheological, mechanical, thermal and morphological properties

Abstract

AbstractLow density polyethylene (LDPE) and agar were blended by using the former as an internal mixer and varying the amount of agar. Resulting blends were hot pressed and characterized with regard to their torque‐rheological, mechanical, dynamic‐mechanical, thermal, and morphological properties. The torque rheological properties were determined using classical power law model. Tensile properties of LDPE‐agar biocomposites showed that agar improves the tensile modulus (stiffness), but compromise the tensile strength and elongation at break. Viscoelastic behavior of the matrix is clearly influenced by the presence of agar biofiller as shown by the dynamic mechanical analysis (DMA). Thermal behavior of the biocomposites was also investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Morphological observations by scanning electron microscopy (SEM) show the ductile to brittle fracture of LDPE‐agar biocomposites subjected to tensile test. This work is an initial reference to identify potential applications of biocomposites based‐on agar as a biofiller. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers